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today we're diving back into the supercharger and this is the m45 eaton supercharger commonly found
on honda's earlier model d series so this is the inlet tube with the bypass assembly bypass valve
and the common s tube and the throttle body so we'll talk about the throttle body and the s2
uh restrictions and issues i see in a later video right now we're gonna focus on the
throttle valve there the bypass valve and the actuator itself
now when you get these normally the nipple up there is broken
or the diaphragm is inside and it doesn't hold vacuum or rusted closed as you can see mine is
nice and looped up i cleaned everything out got some dry lock lube in there on both sides still
a little carbon i haven't fully cleaned it out yet but in a normal working supercharger application
under vacuum while you're sitting at idle i'm going to draw about
15 hg you see the valve is open
see the valve be open just simulating that you're idling so at this point you're re-circulating the
boost so you're dumping the boost back onto the non-charged side of the supercharger and then if
you hit the throttle that closes and allows you to build boosts faster so a lot of times people
disable these and everything i'm not here to say whether you should or you shouldn't but
it was there from the manufacturer to make the car spool quicker get better gas mileage and i'm gonna
leave it and it's working perfectly fine like i said a lot of times you'll find them busted and
they're you know 150 200 to get them used and i'll show you again this one's doing just fine i'm glad
so we're simulating idle conditions
and if we hit the throttle it would close so you're not re-circulating boost anymore
and you're building boosts otherwise that idle your bypassing boost
because you'd be fighting the engine and the brakes if you're stepping on it with this
thing closed and you're building boost constantly because it's belt driven supercharger all right so
to test your bypass valve bypass actuator you need a vacuum gauge just going to pump it up
open the valve all the way and let it sit now naturally it's going to want to close
because it's under spring pressure and there is slight leaks in between you know
plastic and metal interference but if it's holding like this and going back slowly the valve is
generally good because the engine is going to be constantly producing a vacuum it's if you
have it like this and you're squeezing and this valve doesn't move at all
and doesn't hold itself so mine starts opening at about four inches of mercury
and about ten it's fully open all right i can get to 15 while i'm pumping it let it go
and it'll slowly go back that's really the only check you can do on it
other than making sure it's not rusty and i put a little bit of supercharger needle grease on there
so that it don't bind up i also adjusted the stop valve on it to right before it hits
it's got just a little bit of movement in there and does just fine
looks like before whoever had it
had it adjusted to open way too much and it was resting should just barely be touching that stop
all right we're gonna flip around and look at the inside
all right we got the s tube and the inlet with the bypass valve and actuator assembly
turned upside down so we can look inside and see it's a very minimal pouring that has to be done
it's not too much i'm gonna get all four bolts in there and see and i'll probably
just smooth the inside of this out for a good transition so let me get them bolts in and
let's see how much we actually got to take off okay so we got all four of the bolts in
and just slightly hand tightened it's a little loose i can move it and see and let me zoom in
there we go i'm gonna move it around so you can see there's not much
that has to be taken off and it's a step coming in so there's really no like wall
or blockage because all the flow is coming up through this pipe and out and out this side
so i'll get the grinding stone out and just take a little bit off but i don't see any reason to open
up this port anymore or this port let's flip it around and look at the throttle body side
okay this is the throttle body side so stock these things are 66 millimeters
and this is just a stock d16 z6 throttle body 66 millimeter and again it's fairly close um so
i got an aftermarket 66 millimeter one it's billet aluminum so i'll put that
on here and then i'll see if i actually got a and do any smoothing or anything in there
but yeah that's the end of it and let me get this thing set back up so we can talk about the s-tube
all right here we got the s-tube and if you can see it comes in
the air would rush in through here and it hits a wall it has to come down hit another wall and
then go into the supercharger to get compressed um there's a couple companies out there that make
or are trying to make new s tubes and everything which is great um hopefully we'll see those soon
this was designed strictly to bolt onto the oem honda system i don't think um moss uh
was it moss motors or whoever owned jackson at the time i may have been jackson themselves
this was supposed to be just a bolt on and go you know 75 horsepower however much it put out
you know at six psi so i've been thinking maybe in the future i'll cut
and bring this down you know just bring this whole section down and get rid of that bend
but for now i'm going to leave it alone and just do a minimal pour out of the throttle body match
it with the new one i got mat port match this and port match the other ones and just have everything
port matched and smooth and operating like it's supposed to so it's a fun enjoyable daily driver
this is not going to be on a race car or anything it's gonna be a daily that gets good gas mileage
so yeah stay tuned for the next video where i port match everything and start making gaskets
for everything thanks for watching please subscribe